CONDITIONS REQUIRED FOR TRANSFORMER PARALLEL operation are..
1. Voltage turn ratio.
2. phase sequence
3. Impedence should be same
4. polarity
Hitesh
Followings are merits and demerits of parallel operations of transformers: Merits 1. Increasing load demand on substation can meet by connecting transformers in parallel. 2. Maintenance of individual transformer with low rating (Instead of one Big transformer with high rating)becomes easy and can be done without affecting power supply. 3. In case of any fault, faulty transformer can be removed from the system and others may continue feeding the load. 4. Power reliability of substation is increased. Demerits 1.Parallel operation needs very much attention and correctness. 2.Phase sequence , Voltage Ratings , % impedance drop and polarities these few things comes in picture which needs to be taken care when doing parallel operation.
It is required to connect a second transformer in parallel with the first transformer if the load exceeds the rating of the transformer shown in Figure 1.46. The primary windings are connected to the supply bus bars while the secondary windings are connected to the load bus bars. During paralleling of the transformer, similar polarities of the transformers should be connected to the same bus bars shown in Figure 1.46. Otherwise, the two emfs induced in the secondary windings with incorrect polarities will produce the equivalent of a dead short circuit shown in Figure 1.47.The following conditions are important for parallel opera-tion of transformers:The voltage ratings of both the primary and the secondary of the transformers should be identical. Small differences are permissible if the resultant circulating currents can be tolerated.The connections of the transformers should be proper with respect to their polarities.The percentage impedances should be equal in magnitude and the X/R ratio must be the same to avoid circulating current and operation at different power factors.The equivalent impedances must be inversely proportional to the respective kVA ratings.The above conditions must be satisfied by paralleling transformers of identical ratings of the same make/model. With different kVA ratings of even the same make/model, the effects in steps 1, 2 and 3 may appear in undesirable amounts. Step 2 must be carried out satisfactorily even if steps 1, 3 and 4 are slightly modified.Figure 1.46 Parallel Operation of TransformersFigure 1.47 Parallel Operation of Transformers with Incorrect Polaritiesby keshav basyalpokharauniversitypokhara nepal
Knowing the polarity of transformers is important if they are to be connected in parallel.
the necesscity of two three phase transformers operating in parallel are as follows...if the one transformer fails to give supply,then another transformer can be used in parallel and hance,continuity of supply can be maintained.one transformer can be easily take out from the supply for repair & maintanance.if the load on the substation increases beyond the rated values of transformer, then another transformer can be used to share rhe load of the substation.
what is ynd1
The vector group of a transformer is important for determining the phase relationship and polarity of the transformer windings. It helps ensure proper operation and connection of the transformer in the electrical system. Additionally, the vector group is essential for parallel operation of transformer units to avoid phase shifts and ensure synchronization.
It enables an existing transformer to be upgraded to meet an increase in load, without having to remove that transformer and replace it with a 'larger' (expressed in volt amperes) one. It provides an useful way of using up a stock of smaller transformers.
Followings are merits and demerits of parallel operations of transformers: Merits 1. Increasing load demand on substation can meet by connecting transformers in parallel. 2. Maintenance of individual transformer with low rating (Instead of one Big transformer with high rating)becomes easy and can be done without affecting power supply. 3. In case of any fault, faulty transformer can be removed from the system and others may continue feeding the load. 4. Power reliability of substation is increased. Demerits 1.Parallel operation needs very much attention and correctness. 2.Phase sequence , Voltage Ratings , % impedance drop and polarities these few things comes in picture which needs to be taken care when doing parallel operation.
current increase in series operatio and transformer will b damaged
synchronise means parallel operation. to do so first you must understand the winding level chaos. what is 30 deg and -30 deg. then automatically you can come to a conclusion
Yes it can
A transformer is a static device which is used to step up or step down the voltage in a powered circuit.
vibration of the transformer's laminated core in response to the AC magnetic field.
The maximum efficiency condition in distribution transformer is said to be occurred when iron loss = copper loss
specially for high voltage operation
when two transformer are connected in parallel condition,and the polarity of transformer are opposite to each other then a large circulating current flow through out the winding,therefore a very small current flow thro, the load .therefore lifespan of transformer will be reduced.
Transforming a signal without changing its frequency.(amplitude can be changed)